As a rule critics pay little attention to friendship in music. Instead we talk about collaboration, with its implicit emphasis on labor, as if ensemble music were a task on a par with roofing a house. Thursday evening’s concert by Wu Man and the Knights at Asia Society was a refreshing reminder of how much music gains when it is performed by friends who delight as much in their art as in one another’s company.

Ms. Wu is today’s leading performer on the pipa, the Chinese plucked string instrument that looks like an upright lute. Through the Silk Road Project she befriended the violinist Colin Jacobsen and his brother Eric, a cellist. The Jacobsen brothers are the driving force behind the Knights, an orchestral collective conducted — when a conductor is needed — by Eric Jacobsen. The group grew out of late-night chamber-music-reading parties they hosted in their Brooklyn home in the late 1990s. Today their performances still have the feel of a pickup game of basketball in the park.

The concert opened with a gutsy rendition of Stravinsky’s “Dumbarton Oaks” concerto, which the Knights played standing up, without a conductor. Crisscrossing lines of communication became visible in the players’ facial expressions and body language: Cellists smiled at each other over a shared joke of offbeat pizzicati. Two violinists leaned into each other with hurts-so-good grimaces as they dug into one of Stravinsky’s more scrumptious dissonances.

The concerto for pipa with string orchestra by Lou Harrison seems to require that sort of shared sense of humor and trust. It’s a delightful piece that traverses musical worlds spanning Chinese folk songs and Vivaldi. For Ms. Wu it provides an opportunity to show off the polyglot range of her instrument, which can produce translucent beads of sound as well as sustained singing phrases.

Ms. Wu also presented one of her own compositions, “Blue and Green,” arranged for pipa and orchestra by Lev Zhurbin and Colin Jacobsen, in which she draws on folk melodies she encountered during her travels through China, and a tune borrowed from her young son. The Knights seemed to delight in this game of cross-dressing, in which sounds resembling Chinese instruments came out of a Western orchestra. For a few bars a group of them broke into song.

A fascination with travel and color also informs Debussy’s “Prélude à l’Après-midi d’un Faune,” which the Knights played in an arrangement by Michael P. Atkinson that heightened the daring nature of its writing for wind instruments. Alex Sopp played the flute solo with exquisite expression, while Eric Jacobsen’s direction created a meticulously balanced sound.

Humor asserted itself again in “Le Boeuf sur le Toit,” by Darius Milhaud. Not every note of this raucous dance score was in perfect place, but with players beaming as they shimmied and swayed, it felt more like a cast party anyway.